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Finding the Fourth Proportional to 370.40, 555.20 and 139.20

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Solution

The fourth proportional to 370.40, 555.20 and 139.20 is: 208.65

Step by Step Solution

  1. Step 1: Write the proportion equation
    370.40 : 555.20 = 139.20 : x
  2. Step 2: Convert to fraction form
    370.40/555.20 = 139.20/x
  3. Step 3: Cross multiply
    370.40x = 555.20 × 139.20
  4. Step 4: Simplify right side
    370.40x = 77,283.84
  5. Step 5: Solve for x
    x = 77,283.84/370.40
  6. Step 6: Final answer
    x = 208.65

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.